Congeneric apparatus for melt spinning and windup of synthetic yarn is described in WO 2004/015173 A1.
It is common general knowledge in the arts of producing synthetic yarn that the synthetic yarns are each extruded in a parallel side-by-side arrangement in a spinning appliance from a polymer melt to form a multiplicity of strands of filament, which are cooled down and bundled. The yarns are subsequently guided in parallel, preferably by godet systems, in a treating appliance to then be wound up in a parallel manner at the end in a windup machine to form bobbins. In the process, from the melt spinning stage to the windup stage, the yarns are guided with different yarn spacings relative to each other. Initially, in the spinning appliance, a spin spacing is maintained between each of the yarns, which is essentially due to the die pitches of the spinneret die packs. After cooling, the yarns are gathered together to be guided conjointly through the treating appliance spaced apart by a significantly smaller treatment spacing. The treatment spacing is essentially maintained between the yarns up to before entry into the windup machine. In the windup machine, a wind spacing must be maintained between the yarns, which is essentially due to the width of the bobbins of the individual winding stations. The yarn sheet thus undergoes spreading apart from the treatment spacing to the wind spacing.
The areas of transition between the spinning appliance and the treating appliance and also between the treating appliance and the windup machine are thus provided with yarn guiding means adapted to allow individual yarns to be diverted or deflected to the particular yarn spacing desired. In addition, it has to be ensured that the yarns can be guided safely and without mutual contact in the appliances, particularly in the godets of the treating appliance. Care must further be taken to ensure that the diversions generated by yarn guiding means do not generate impermissible yarn tensions due to high wrap friction. In this respect, certain angles of diversion have to be observed in the regions of transition, in particular in relation to the yarns on the outside. An additional aggravation in relation to the windup of the yarns is that each friction-based deflection on the yarn leads to an increase in the yarn pulling force and thus influences the winding tension at the windup of the yarn on the bobbin.
Recent developments for optimizing yarn travel relate particularly to the yarn transition from the treating appliance to the windup machine.
WO 2004/015173 A1 discloses apparatus wherein the yarns are distributed via a runoff godet situated above the windup machines in a horizontally oriented runoff plane and essentially transversely to the longitudinal axis of the windup machine. Placing the runoff godet at a front end of the windup machine makes it possible to effect distribution out of the runoff plane, so that low spacings are achievable between the windup machine and the treating appliance, which lead to compact and hence handling-friendly machine designs.
WO 2004/074155 A1 discloses a further apparatus wherein the yarns are distributed to the winding stations of the windup machine through a runoff godet disposed vertically and to the side of the windup machine. Here, the yarns are led in a vertically oriented runoff plane which is positioned in relation to the winding stations such that simple diversion brings about a distribution into the winding stations.
Both the known apparatuses constitute ways of leading the yarns in the treating appliance parallel to each other and with a very small treatment spacing and subsequently for them to be distributed to the individual winding stations with a larger distance relative to each other. The prior art apparatuses utilize yarn guiding means to obtain certain yarn paths and diversions.
It is an object of the present invention to develop a congeneric apparatus such that a yarn sheet supplied by a treating appliance can be supplied to the winding stations of the windup machine with a minimum of friction and with no significant yarn tension differences.